a) Field of the Invention
The invention is directed to a cable connector for electrical connections.
b) Description of the Related Art
Cable connectors are used for electrical and mechanical connection between an open, movable cable and a mating connector that is stationary or that is also connected with a cable. Aside from a flawless electrical contact and the mechanical connection of the connectors to be coupled, it is very important that the cable is solidly anchored mechanically in the cable connector. This anchoring must absorb all of the forces occurring between the connector housing and the cable, i.e., it must prevent relative movement between the connector housing and cable when the cable is let in. Above all, this is a matter of transferring the tensile stresses introduced via the cable directly to the connector housing and keeping them away from the mechanical connections of the inner conductors of the cable and the contact elements of the connector, i.e., so that the latter are not mechanically loaded by the above-mentioned tensile stresses. A further object to be met by a strain relief or pull relief of this kind is a simple mounting of the connector on the cable, the fastening of the connector with the fewest possible number of parts. As a rule, a cable connector comprises a housing which is preferably made of metal for reasons pertaining to shielding, a contact element carrier which is made of electrically insulating plastic and which is to be received by the housing, and a pull relief device which absorbs tensile and bending forces acting on the cable, conducts these forces to the connector housing and keeps them away from the contact element insert. In their commonest construction form, the contact elements are constructed as pins or as conjugating, springing sockets which are inserted into the contact element carrier. The mechanical, generally lockable, connection of a connector of this kind with the mating connector can be carried out in various ways, e.g., by means of a locking jack mechanism, a coupling ring or also, with respect to force, by the arrangement of corresponding spring elements.
Various constructional measures, e.g., screw straps, screw clamps, collet chucks, positive-locking cable anchoring by means of a twisting arrangement of the cable and the like, are provided for the above-mentioned pull relief which should advantageously be effective for a certain range of diameters.
In this context, particularly with respect to the pull relief mentioned above, reference is had to the previously known constructions according to DDR 83 391, DE 28 43 628 A1 or GB 2 261 775, all of which show and describe swiveling jaws which form the pull relief by contacting the cable inserted into the cable connector. In the construction according to DDR 83 391, mentioned above, a plurality of swiveling jaws of this type are connected with one another via a deformable ring or ring segment and the construction element designed in this way lies exposed in the housing of the cable connector. When assembling, care must be taken to insert this structural component part in the correct position so that it can perform its intended function. It is also necessary to be careful not to lose this structural component part when assembling, since this structural component part is arranged loosely in the housing. The toothed washer used as pull relief in DE 28 43 628 A1 has an elaborately shaped form which is received in a likewise elaborately shaped bearing by means of a spring pin and a clamping pin. The construction known from GB 2 261 775 A shows bracket-like bent jaws which are provided in pairs and which are connected with one another by one end via a laterally arranged crosspiece. This pull relief requires a relatively large width and is therefore only usable within limits, in particular only in combination with electrical devices which are outfitted with cables, but not in cable connectors under very cramped conditions.
Further, a two-part plug-in connector is known from DE 27 00 197 A1. Its first part has a portion receiving contact elements and an adjoining shell-shaped portion. The second part can be connected with the shell-shaped portion of the first part to form the complete connector. The second part has clamping ribs for cable pull relief.